<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>后代选择器</title>
</head>
<body>
    <!-- div 里面的 span 文字颜色是红色 -->
     <!-- 后代选择器:选中所有后代:包含儿子\孙子... -->
      <style>
        div span{
            color: red;
        }
      </style>
</body>
    <span>span 标签</span>

    <div>
        <span>这是div的儿子</span>
        <p>
        <span>这是div的孙子</span>

        </p>
    </div>
</html>